Porous solid materials are important in many areas of modern science and technology, including ion exchange, molecular separation, catalysis, chromatography, microelectronics, and energy storage. Notable examples are microporous (<2 nm) zeolites and mesoporous (2-50 nm) silicate and carbonaceous materials. The ability to manipulate the structure and morphology of porous solids on a nanometer scale would enable greater control of chemical reactions.
Previous studies on the interdiffusion of 30-micrometer powders with layered composition showed significant porosity, but the geometry and distribution of the pores were not uniform, probably due to aggregation and still bulk-like dimension of the particles. Recently, significant progress has been made in synthesizing colloidal nanocrystals with well-controlled size, shape and surface properties.
Hollow particles of silica have been made with diameters between 720 and 1000 nm, see Science, Vol 282, Issue 5391, 1111-1114, 6 Nov. 1998, the contents of which are hereby incorporated by reference in its entirety for all purposes.
Gold single crystalline nanoboxes have been made, though not on the nanoscale size dimension as taught by the present invention, see Y. Sun, Y. Xia, Science 298, 2176 (2002), the contents of which are hereby incorporated herein in its entirety for all purposes.